Film printing machine



Oct, 17,1933. A. J; BRADFORD FILM PRINTING menus riled Jpn. a. 1m

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Patented a. 11, 1933 mm OFFICE.

1,931,128 I 1 mm ram'rmu mourns Arthur J. Bradford, Detroit, Mich,assignor to General Electric Company, a corporation of New YorkApplication January 24, 1931. Serial No. 511,037

Claims. (o1. 88-24) My invention relates to film printing machines whichare provided with adjustable apertures for regulating the amount ofexposing light. Machines of this character heretofore constructed i formaking prints of motion picture films which were of such a characterthat changes in light were required for difierent parts thereof wereprovided with means under the control of the negative film for stoppingthe machine when-- ever a point is reached at which a change in light isrequired. The operator has then made the proper change in the lightaperture and restarted the machine. Such a procedure is objectionablesince it' causes a loss of time and extra wear on the machine due tofrequent starting and stopping. Moreover, when the machine is used toprint a sound record at the same time as a picture. record, stopping ofthe machine before the end of the film is reached causes a fogged spotin the sound record which results in an unpleasant noise when the recordis reproduced. My invention has for its object the provision of animproved film printing machine I which is simple, efiicient and avoidsthe above noted objections. .In accordance with my invention I haveprovided the machine with an aperture.,.presetting apparatus,semiautomatic incharactenby' which the'operator may pre-set A theapparatus for the next change in aperture 39 adjustment and when theproper time for the change is reached the machine will automaticallymake the adjustment for which it was preset. a 1 My invention will bebetter understood from --rthe following description taken in connectionwith the accompanying drawing. and its scope will be pointed out in theappended claims.

Referring.- to the drawing in which the single figure represents anembodiment of my invention applied to an optical printer, light from thelamp 1 is concentrated by the condensing lens 2 on the film 3,- such asa negative, from which the print is to be made. Between the negative 3and the print film 4 is the obiectiveb by which an image of the negativeis formed on the film 4. The apparatus above described is shown in amore or less diagrammatic manner, the enclosing casings, masks and mmdriving apparatus being purposely omitted in the interest of cleamess inthe illustration. Associated with the lens 5 and in the present casehaving the same mounting is the iris diaphragm 6 by means of whichtheamount of exposing light is controlled. The iris diaphragm is adjustedby means of the gear segment 7 meshing with which is the pinion 8mounted on the shaft 9. Secured to shaft 9 is the actuating disc 10having the forwardly extending car 11 and a series of peripheral notches12. This disc 10 is retained in various adjusted positions by the detent14 which is normally held in engase- 60. ment ,with one of the notchesin the disc by the spring 15 but which is adapted to beelectromagnetically withdrawn therefrom by the coil 16 acting upon themagnetic plunger 17 carried by the detent. For closing'the circuit ofthe coil 16 I have shown a film controlled switch having cooperatingfixed and stationary contacts 18 and 19, the latter contact beingcarried by the spring pressed arm 20. Carried also by this arm is theroller 21 which is arranged to engage one edge of film 3, this edgebeing shownas provided with a notch 22 which is of such a depth thatwhen the roller drops into the notch the contacts 18 and 19 are closed.The film 3 is provided with a notch such as shown at 22 at each pointthereof 7E;v at which a change in the setting of the diaphragm isrequired. Loosely mounted on the shaft 9 is the pre-setting arm 24, theouter end of which is shown pointed and cooperates with the scale anddetent plate 25. ,Arm 24 also is provided near g0- its outer end withthe springpressed detent 26 i which is adapted to engage in any one of aplurality of-openings 27- thereby retaining the arm against displacementand in a position pointing to one or another of the several indicia 28which 35'. refer to various degrees of diaphragm opening. Also looselymounted on shaft 9 are the two arms 30 and 31 each having at'its outerend a cross bar 32 of suflicient lengthto overlap the presetting arm 24and the car 11 on disc 10, itbeing 9m noted that the cross bars 32 arearranged respectively at opposite sides oiLthe arms 30' and 31'. Twospiral springs 34 and 35 each have their inner ends secured to the shaft9 and their outer ends attached by short pins to the respective arms 30and 31. These springs are under a certain amount of initial tension sothat when the disc 10 is released by detent 14,'it will be moved in onedirection or the other so as to bring the arms 24, 30 and31 and the car11 into alignment.

In the operation of the apparatusv when the printing operation isstarted the pre-setting arm 24 is set to the proper point on the scaleto give the desired exposure for the first section of the film.The,;disc 10 may be released by manually closing the contacts 18 and 19or if desired by manually withdrawing the detent 14. At any time duringthe printing of this first section 'of the film the operator resets thearm 24 to-glve the exposure desired for the next "section of the film.110

The setting of the diaphragm, however, does not change immediately sincethe disc .10 is retained by the detent 14 until the next section of thefilm is reached when the roller 21 dropping into a notch, such as shownat 22, closes the circuit of coil 16 to thereby withdraw the detent 14.Upon withdrawal oi. the detent 14 the disc 10 is ireeto be rotated byone or the other of the springs 34--35 to rotate the disc 10 to aposition in which the ear 11 thereon aligns with the arm 24 and thusadiusting the iris diaphragm to the new setting. v

It will be seen that by reason 01 this construction the presetting arm24 may be moved in either direction to change the setting of thediaphragm,

the double spring arrangement always causing the-disk 10 to followthepresetting arm when released by the detent 14. It may be founddesirable to employ suitable means to dampen the movement of the disk 10and to provide cushioning .means between the ear 11 and the cross bars32 to reduce noise and vibration.

I have chosen the particular embodiment described above as illustrativeof my invention and it will be apparent that various modifications maybe made without departing from the spirit and scope of my inventionwhich modifications I aim to cover by the appended claims;

.whatlclaimasnewanddesiretosecureby letters Patent oi the United States,is:

1. Aperture presetting apparatus for a film printing machine comprisingan aperture varying member, means for retaining said member, againstmovement; a pair of resilient members between the aperture y ng memberand the retaining means having initial tension and tending to rotate theaperture v ying member respectively in opposite directions, a presettingmember arranged to increase the tension of the respective resilientmembers when moved in opposite directions and means controlled by thefilm for releasing said retaining means.

2. Aperture presetting apparatus for a film-- printing machinecomprising an aperture varying member, means for retaining said memberagainst movement, a pair of springs under initial tension between themove the aperture varying member in opposite directions, a movablepresetting member arranged to be retained in any one of a plurality ofpositions and having means for increasing the tension of the respectivesprings in response to movement of the presetting member in onedirection or the other and means controlled by the film ior releasingthe retaining means.

3. Aperture presenting apparatus for a film printing machine having aniris diaphragm comprising a rotatable member operatively connected withsaid diaphragm, a retaining device for said member, a rotatablepresetting arm, means comprising a plurality oi springs each having oneend secured to the rotatable member arranged to move the member ineither direction to cause it to follow the arm, and means controlled bythe film for releasing the member.

4. In an optical film printing machine having an iris diaphragm,presetting apparatus for said diaphragm comprising a rotatable memberoperatively connected with said diaphragm. a detent tor said member, arotatable presetting arm having means for retaining it in'a setposition. a pair of springs each having one end operatively connectedwith said member and having their opposite ends arranged to be moved bythe presetting arm, and film controlled means for withdrawing thedetent.

5. In an optical film printing machine having an iris diaphragm,presetting apparatus for said diaphragm comprising a shaft operativelyconnected with said diaphragm, a disk securedto the shaft and havingdetent notches therein, a detent arranged to engage in said notches,means controlled by .the record film for withdrawing the detent, aplurality of arms loosely mounted on said shaft, a plurality of spiralsprings each having one end secured to the shaft and having theiropposite ends connected with the respective arms, a presetting armloosely mounted on said shalt, a cooperating scale, and a detent carriedby the presetting arm arranged to engage said scale, said firstmentioned arms having end portions arranged respectively to engageopposite sides of the presetting arm and said disk.

ARTHUR J. BRADFORD.

